The Guerrilla Care Package was formerly a preorder bonus if you bought Homefront from GAME in the UK, it's now been made available to purchase on its own. This DLC contains five Resistance Crates that will allow you to unlock items in the game's four player co-op Resistance Mode before you would normally earn them. The high price of this DLC and that it contains no original content makes this a very poor purchasing decision.
If you are enjoying the game enough to play through the co-op mode with friends you are likely going to be able to unlock whatever random equipment you would have gotten form purchasing this DLC.